A highly integrated optical space switch is known, for example from an essay by L. Thylen and P. Granestrand, which was made public at the 1990 Globecom 90 in San Diego, (USA), and which is also available as a conference paper. As shown in FIGS. 4 and 8 of this essay, this space switch consists of a very large number of optical branches. Each branch contains monolithically integrated, optically active and passive areas, whose construction e.g. can be seen in FIG. 7. Optically active areas in both arms of each branch serve to control a portion of the light passing through the respective arm.
The manufacture of the optically active and passive areas of the above named optical branches on a substrate is described in detail in a publication by Ericsson Telecom AB, Stockholm, Sweden under the title "Monolithically Integrated 2.times.2 In Ga As P/In P Laser Amplifier Gate Switch Arrays". It comprises a number of process steps, in which layers are grown or selectively eliminated. The different deposition and etching methods of the manufacture require the substrate to be treated in different containers, and therefore it has to be repeatedly repositioned and readjusted.